Acrolein is a simple unsaturated aldehyde compound including an incomplete reactive group and having high reactivity, and the main uses thereof are as an intermediate in the synthesis of numerous compounds. In particular, acrolein has been widely used as an intermediate in the synthesis of acrylic acid and its esters, superabsorbent polymers, animal feed supplements, food supplements, etc.
Conventionally, acrolein has been prepared by a selective gas-phase oxidation reaction with atmospheric oxygen using a starting material, propylene, which is obtained from the processing of petroleum. However, as reduction in fossil fuels and environmental problems such as the greenhouse effect gradually emerge, many studies have been conducted on a synthetic method of producing acrolein using renewable non-fossil fuel based raw materials.
Accordingly, a natural product, glycerin, obtained as a by-product of biodiesel production, has gained much interest as a raw material for acrolein synthesis. In particular, as the production of biodiesel increases, the glycerin market is expanding, and due to reduction of glycerin price, industrial applications thereof have been studied.
For example, there is known a method of obtaining acrolein by dehydration of glycerin in the presence of a catalyst, and the method is known to be performed by using an acidic catalyst such as zeolite, phosphorus oxide, and tungstophosphoric acid (H3PW12O4).
However, since the catalysts which were previously used to prepare acrolein from glycerin produce by-products such as hydroxy acetone, hydroxy propanone, propane aldehyde, acetaldehyde, acetone, and polycondensation products of glycerin, there is a limitation in the use of the catalysts for the production of acrolein with high purity. Further, there is a problem that when the catalyst is supported on a carrier, the catalytic activity is rapidly reduced.
Accordingly, there is a demand to develop a method for preparing a catalyst for glycerin dehydration, which is able to minimize by-product formation to improve selectivity and purity of acrolein and conversion ratio and reaction yield of glycerin, and to maintain high catalytic activity even though supported on a carrier.